Combined charging and pressure indicating device

ABSTRACT

A pressure gage has a charging inlet positioned in the center of the dial of the gage, in addition, the closure for the charging inlet is used for releasably making the pressure gage watertight.

United States Patent 1191 [111 3,777,569 Krulee Dec. 11, 1973 1 41COMBINED CHARGING AND PRESSURE 1,061,472 5/1913 Hackley 73/146.8

INDICATING DEVICE 3,380,427 4/1968 Rubin 73/146.8

[75] Inventor: Alfred W. Kruiee, Chatham, NJ. [73] Assignee: NorrisIndustries, Inc., Los Angeles, Primary Ex i r-Donald O, woodiel Ca11f.AttorneyEdward T. Connors [22], Filed: June 21, 1972 [21] Appl. N0.:264,776

1 [57] ABSTRACT [52] US. C1 73/389, 73/418, 137/227 [51] 1nt.C1. G01119/00 [58] Field 61 Search 73/l46.3, 146.8, A PYassure gage has chargmgP051110cl the 73,389, 411, 137/227 center of the dial of the gage, inaddition, the closure for the charging inlet is used for releasablymaking the [56] References Cited pressure gage watertight.

UNITED STATES PATENTS 1,893,222 1/1933 Bronson 73/146.8 2 Claims, 3Drawing Figures IV- 25 E7 26 35 \I \J: I 8 12 l "I J N I 3 6 I 7PATENTEU DEC 1 1 i975 FIG. 2

FIG/

FIG. 3

COMBINED CHARGING AND PRESSURE INDICATING DEVICE side of the valve andthe charging fitting has been positioned on the opposite side thereof orat a separate location.

In the early fire extinguishers the pressure gage was of thepressure'tube or so-called Bourdon type with a gear arrangementpositioned between the tube and the pointer. More recently, in lessexpensive constructions, the gearing is omitted from the gages and thepressure tubes are made with a plurality of turns with pointers at thefree ends thereof. It was easy with the early gages to ascertain whetheror not the pointer was sticking by tapping the gage, and because of thehigh gear ratio between the pressure tube and the pointer, the pointerwould vibrate; In the later gages which omit the gear ratio there is nosignificant movement of the pointer when the gage is tapped.

Safety regulations, in some cases, require that fire extinguishers beinspected monthly. Of course, while the gage may show that there isample pressure in the extinguisher, the gage may have become stuck andbe indicating pressure while in fact the pressure may have dropped belowthat required to expel the fire extinguishing agent in a satisfactorymanner. Therefore it is necessary periodically to check the accuracy ofthe gage reading.

The combined charging and pressure indicating device in accordance withthe invention overcomes a difficulty had with prior constructions inthat in accordance with the invention the charging opening is positionedin the center of the dial of the pressure gage so that it is readilyavailable for connection to a separate testing gage or to a pressuresource. In addition the usual inlet valve of the charging opening may beused to relieve the pressure safely in the event it is desired todisassemble the extinguisher.

In the manufacture of dry chemical fire extinguishers on a productionbasis it is extremely important that any potential leaks be detected ina fast and economical manner. This testing is usually done byincorporating with the pressurizing gas a small amount of a trace agentsuch as a halogen, or helium. Thus if there is any leakage of thepressurizing gas it may be readily detected by a halogen leak detectoror by the use of a mass spectrometer. The use of these test instrumentsis complicated somewhat by a regulation which requires that the pressuregage be watertight as many of the fire extinguishers are destined formarine use. This makes it difficult to test the gage itself for smallleaks, thus to effectively test the completed extinguisher with itspressure gage in place it has been the practice, in some cases, toperforate the case or crystal of the pressure gage with a small hole soas to detect any leak from within the gage. It is necessary thereafterto seal the small hole to restore the water tightness of the pressuregage.

The construction in accordance with the invention lends itself toproviding means for opening the interior of the pressure gage for leaktests and for closing it immediately thereafter. This closure means isachieved by a seal closed by the cap for the valve of the chargingmeans. i

The device in accordance with the invention thus includes a charginginlet positioned'in the center of the dial of the gage, the closingmeans for the charging inlet releasably making the pressure gageinterior watertight.

In the drawings:

FIG. 1 is a front view of a combined charging and pressure indicatingdevice in accordance with the invention.

, FIG. 2 is a view corresponding to FIG. 1 with the dial removed showingthe construction of the pressure tube with a pointer.

FIG. 3 is a sectional view of the combined charging and pressureindicating device at an enlarged scale.

Referring to the drawings there is shown a combined charging andpressure indicating device 10 in accordance with the inventioncomprising a supporting body member 11 having a fluid passage 12extending therethrough. In fluid communication with an increaseddiameter portion16 of the fluid passage 12 is a pressure tube l4carrying an indicating. pointer, 15 at its outer end. Alternatively, asis known in the art, the pointer 15 may be connected to the pressuretube by a gear mechanism not shown. The fluid passage means 12 isprovided with a threaded area 17 to receive an inlet type valve assembly18 which includes, as is well known in the art, a spring 20, sealingmeans 21, a threaded outer surface to engage the threaded surface 17,and a valve stem 22 adapted to unseat valve member 24 against the actionof the spring 20. The outer end of the supporting body 11 may bethreaded as indicated at 25 to receive a cap member 26 having a threadedinterior surface, or the cap member may be otherwise attached forexample as by a snap fastening (not shown). The end of the supportingbody member 11 about the fluid passage 12 is shown as provided with atapered threaded surface 27 for securing the gage device in position inthe wall of a pressure vessel or in the wall of a valve. Alternativelyother means may be used for securing the gage device in position. Anenlarged portion 29 of the supporting body 11 may have a surface shapedto receive a wrench or other tool for tightening the device in positionin use.

A dial 30 is carried by the supporting body 11 and is provided withindicia as indicated in FIG. 1 showing an operable pressure range in thearea 31, while if the pointer were in the area 32 it would indicate thatthe extinguisher should be recharged. If thepointer were in the area 33an indication would be given that the pressure vessel was overcharged.

The dial 30 is carried against a shoulder 34 and may be held in place bya lock ring 35 or by other suitable construction. The dial 30 isprotected by a transparent face 36 which is suitably apertured toreceive charging end 37 of the supporting body 11. The gage has a case38 swaged or otherwise attached to the enlarged portion 29 as indicatedat 39. The case 38 has a cover member 40 holding the transparent face 34in a watertight manner. The cap member 26 may have a knurled outersurface to facilitate its removal and it may have a flange 41 engaging agasket 42 so that the body of the pressure gage may be releasablysealed. The cap member 26 may be removed or loosened so that a leaktester may explore the gage for leaks therein after which the cap member26 is screwed into position restoring the watertightness of the case. Insome instances it may be preferable to seal the transparent member 36 tothe charging end 37 of the supporting body 11.

While the invention has been described and illustrated with reference toa specific embodiment thereof it is to be understood that otherembodiments may be resorted to without departing from the invention.Therefore, the form of the invention set out above should be consideredas illustrative and not as limiting the scope of the following claims.

I claim:

1. A combined charging and pressure indicating device of the typeincluding a supporting body having a fluid passage therethrough, fluidpressure responsive means carried by said supporting body in fluidcommunication with said fluid passage, pressure indicating means forsaid fluid pressure responsive means, charging means carried by saidsupporting body in fluid communication with said fluid passage, wherebyboth charging fluid and fluid for pressure indication is passed throughsaid fluid passage, said supporting body straight line through thelength of said body, an inlet valve member being positioned within saidfluid passage, said fluid pressure responsive means being a pressuretube, said pressure indicating means incorporating a pointer movable bysaid fluid pressure responsive means, said pressure indicating meansincorporating a dial, a casing incorporating a transparent viewingmember being carried by said supporting member, said charging meansextending through said transparent viewing member, the improvementwherein vent means is provided for said casing for possible leakstherein from said fluid passage means and/or said pressure tube, and acap member is provided for said charging means, said cap member beingadapted to provide a seal between said charging means and saidtransparent viewing member and to releasably seal said vent means.

2. A combined charging and pressure indicating device according to claim1 in which said transparent viewing member is apertured at its centerand is carried by said supporting member said aperture being somewhatlarger than said supporting member so as to provide said vent means.

1. A combined charging and pressure indicating device of the typeincluding a supporting body having a fluid passage therethrough, fluidpressure responsive means carried by said supporting body in fluidcommunication with said fluid passage, pressure indicating means forsaid fluid pressure responsive means, charging means carried by saidsupporting body in fluid communication with said fluid passage, wherebyboth charging fluid and fluid for pressure indication is passed throughsaid fluid passage, said supporting body being an elongated memberhaving a connecting end for engagement in an opening of a pressurevessel, said fluid passage in said supporting body extending in astraight line through the length of said body, an inlet valve memberbeing positioned within said fluid passage, said fluid pressureresponsive means being a pressure tube, said pressure indicating meansincorporating a pointer movable by said fluid pressure responsive means,said pressure indicating means incorporating a dial, a casingincorporating a transparent viewing member being carried by saidsupporting member, said charging means extending through saidtransparent viewing member, the improvement wherein vent means isprovided for said casing for possible leaks therein from said fluidpassage means and/or said pressure tube, and a cap member is providedfor said charging means, said cap member being adapted to provide a sealbetween said charging means and said transparent viewing member and toreleasably seal said vent means.
 2. A combined charging and pressureindicating device according to claim 1 in which said transparent viewingmember is apertured at its center and is carried by said supportingmember , said aperture being somewhat larger than said supporting memberso as to provide said vent means.